Electrophysiological identification of serotonergic neurons in the rat nucleus raphe magnus

In the present study, antidromically activated raphe-spinal neurons in the nucleus raphe magnus are found to exhibit a wide range of conduction velocities and spontaneous discharge rates. The unit activities observed in control rats have been compared with those in 5,6-dihydroxytryptamine (a specific neurotoxin to serotonergic cells)-pretreated animals. It is found that the units conducting at slower than 12 m/sec and discharging at rates of less than 3 Hz often found in control rats are not found in drug-pretreated animals, and are thus presumed to be serotonergic. In addition, the regularity of spontaneous discharges of units has been evaluated by testing the coefficient of variability of spike intervals. These results indicate that the slow-conducting units discharge less regularly than the fast-conducting ones.

Factors influencing morbidity and mortality of renal transplantation in a high risk population

A group of 37 patients with 39 renal transplants were studied from January 1971 to June 1974, in which 32 were considered at high risk by well defined cardiovascular, gastrointestinal, cerebral vascular, or pulmonary disease or age categories. Three of the 37 patients have died, and two patients in the high risk group, 92 per cent. Eighty-eight per cent of the entire group have functioning kidneys at present, and 93 per cent of those in the high risk group have functioning kidneys. Evaluation of pretransplant mixed lymphocyte cultures, HL-A antigen, and immune responder status; close follow-up observation of lymphocyte culture and humoral responses by in vitro testing; and the use of antilymphoblast globulin are considered to be the reasons for the improved results.